In Zenonia 2 for the iPhone, iPad, and Android system, you can unlock Hard Mode for some added difficulty. To unlock Hard Mode, you just need to finish the game on the default difficulty.
One major benefit to Hard Mode though is the addition of Unique items, which are extremely powerful. You will keep your level, skills, and any items you’ve collected going into Hard Mode, and you will also gain access to an extra (much tougher) boss at the end, but all story aspects stay the same.